TypeScript Cloudflare worker proxy IPFS cloudflare-ipfs.com example

proxy.ts

// SETINGS /////////////////////////////////////
const upstream = {
  domain: 'cloudflare-ipfs.com',
  protocol: 'https',
}

const dns = {
  domain: 'cloudflare-dns.com',
  protocol: 'https',
  path: '/dns-query',
  query: '?ct=application/dns-json&type=TXT&name=_dnslink.'
}

const blockedCountries = ['BY', 'CU', 'IR', 'IQ', 'CI', 'LR', 'KP', 'SD', 'SY', 'ZW']

const headers = {
  'X-Frame-Options': 'DENY',
  'X-XSS-Protection': '1; mode=block',
  'Referrer-Policy': 'no-referrer',
  'X-Content-Type-Options': 'nosniff',
  'Strict-Transport-Security': 'max-age=15780000; includeSubDomains; preload',
  'Feature-Policy': "geolocation 'none'; midi 'none'; sync-xhr 'none'; microphone 'none'; camera 'none'; magnetometer 'none'; gyroscope 'none'; fullscreen 'none'; payment 'none'"
}

// PROXY ///////////////////////////////////////

async function getResponse (origRequest: Request) {
  try {
    const isBlocked = blockedCountries.includes(origRequest.cf!.country)
    if (isBlocked) {
      throw new Error('Unavailable For Legal Reasons')
    }

    const url = new URL(origRequest.url)
    const dnsUrl = `${dns.protocol}://${dns.domain}${dns.path}${dns.query}${url.hostname}`
    const data = await fetch(dnsUrl)
    const json: any = await data.json()
    const txtValue = json.Answer[0].data
    const ipfsPath = txtValue.replace(/.*dnslink=(.*)"/, '$1/')
    url.pathname = ipfsPath + url.pathname
    url.hostname = upstream.domain
    url.protocol = upstream.protocol

    const request = new Request(url.href, {
      body: origRequest.body,
      method: origRequest.method,
      headers: origRequest.headers,
    })

    let response = await fetch(request);
    if (response.status === 404) {
      const cloneURL = new URL(url.href)
      cloneURL.pathname = cloneURL.pathname.replace(/.*(\/ipfs\/\w+\/).*/, '$1')

      const cloneRequest = new Request(cloneURL.href, {
        body: request.body,
        method: request.method,
        headers: request.headers,
      })

      response = await fetch(cloneRequest);
    }

    const responseHeaders = new Headers(response.headers)
    for (const [key, value] of Object.entries(headers)) {
      responseHeaders.set(key, value)
    }

    responseHeaders.delete('Set-Cookie')

    return new Response(response.body, {
      status: response.status,
      statusText: response.statusText,
      headers: responseHeaders
    })
  } catch (err: any) {
    return new Response(err.message, {status: 400})
  }
}

function handleRequest(event: any) {
  const response = getResponse(event.request)
  event.respondWith(response)
}

addEventListener('fetch', handleRequest)